Von Willebrand disease (vWD) is a genetic disorder that prevents normal blood clotting and can cause extended bleeding following injury. The disorder results from a deficiency or lack of sufficient von Willebrand factor (vWf) which functions as a binding protein during blood clotting. Three types of vWD have been identified in dogs to date and are known as vWD type 1, 2 and 3. Within these three types there are five different genetic mutations that are currently known that lead to canine vWD. Von Willebrand’s disease type 3 (VWD3) is a very severe form of the disease in which affected animals produce no von Willebrand Factor protein in their blood. This condition makes affected dogs likely to suffer from abnormal and severe bleeding which can lead to life threatening consequences in common minor injuries or surgical procedures.

Shetland Sheepdog

A (CLEAR/NORMAL): These dogs have two copies of the normal gene and will neither develop von Willebrand’s Disease Type III disease nor pass this mutation to their offspring.

B (CARRIER/NOT AFFECTED): These dogs have one copy of the normal gene and one copy of the mutation associated with this disease. They will not develop von Willebrand’s Disease Type III disease but will, if bred, pass the mutation to 50% of its offspring, on average.

C (AT RISK/AFFECTED): These dogs have two copies of the mutation associated with this disease and are susceptible to develop severe problems with blood clotting.